Over the last few years, physicians in interventional therapy in general and interventional cardiology and interventional radiology in particular have been attempting to find a way to deal with occluded (so called “stenotic”) coronary arteries (among other blood vessels, various tubular conduits and similar structures) in a non-invasive manner while preventing restenosis. The issue is even more pronounced when dealing with bifurcated vessels. A blood vessel or similar conduit, which, along its course, extends a major branch vessel, is termed a “bifurcating vessel”. The structural point of bifurcation, where the main trunk vessel and its side branch vessel meet, is termed the origin of the side branch, and the structure forming the angle between the vessels is termed the “carina”.
Lesions that involve both the main trunk vessel and the side branch vessel are termed “bifurcating” lesions. Such lesions in a bifurcating epicardial coronary artery, involving a major side branch, are quite common. Typically, the side branch itself may contain significant atherosclerotic disease at, or in proximity to, its origin.
Even in cases where the side branch is free of significant lesions, interventional manipulation of the main trunk vessel often results in compromising the side branch by a dissection, thrombus or spasm, or by causing a shift in the position of an atherosclerotic plaque in the main trunk vessel which partially or completely occludes the origin of the side branch. Accordingly, optimal management of bifurcating lesions involves treatment of both the main trunk vessel across the origin of the side branch as well as the origin and/or proximal segment of the side branch. Attempts to treat such lesions have traditionally been by the serial installation of multiple stents or the simultaneous installation of modular stents (i.e. stents comprising a plurality of standardized units for use together in a cumulative group). In particular, attempts have been made to provide devices that allow the deployment of separate stents into each side branch. It would be preferable to provide an integrated stent that comfortably cradles the corina between the arms of the bifurcated stent as each arm of the bifurcated stent is delivered to a respective side branch. In particular, a bifurcated stents, such as the one disclosed in pending patent application Ser. No. 10/190,770, which is incorporated in its entirety by this reference, would be suitable for treatment of both vascular and nonvascular bifurcated vessels. Unfortunately, conventional delivery devices are not designed to effectively and accurately deliver such unitary bifurcated stents to their target site. Therefore, there remains an existing need for apparatuses for accurate and minimally invasive placement and deployment of bifurcated stents. In particular, there is a need for a family of devices that may be indicated for vascular and non-vascular intervention. Moreover, there remains a need for a bifurcated stent placement and deployment apparatus that does not require the use of an ancillary means, such as one or more balloon catheters to achieve complete and precise deployment.
Additionally, there remains an existing need for a bifurcated stent delivery and deployment apparatus that has a safety mechanism to prevent excessive deployment of a misaligned stent. Preferably it would be desirable if the safety mechanism had a physical and/or audible indication means to inform the physician when she has reached maximum reversible deployment. There also remains an existing need for a bifurcated stent delivery and deployment apparatus that increases physician control during stent deployment. Moreover, there exists a need for a bifurcated stent delivery and deployment apparatus that integrally comprises or allows for the insertion of an optical instrument to facilitate stent delivery.
There remains a need for a bifurcated stent delivery and deployment apparatus that also provides working channels for facilitating additional interventional procedures that may be necessary once the delivery and/or deployment process is underway.